As technology and culture continues to evolve, new trends and new products emerge in the market. However, one thing always remains the same: people. The fundamental principles of design hold true regardless of these changes and are applied to new products with adjustments made in account to new activities, technology and methods of communication and interaction. All product designs that are subject to interaction between people and technology can benefit from understanding the principles of psychology, design, art and emotion. Based on these fields, you can leverage these 5 principles of interaction design to build a more satisfying and enjoyable product for people:
Affordances
Â
The relationship between the properties of a product and the capabilities of the agent that determines just how the product could be possibly used is called an affordance. The term is derived from the verb afford. A chair that affords support, affords sitting. The ability to provide support is an affordance that the chair has that allows the capability of sitting. Some chairs are light-weight and hence affords lifting. Here, the light-weight property of the chair is the affordance. However, some chairs are very heavy and don’t support lifting. A relationship in which a property inhibits an action is known as anti-affordance. Hence, the heaviness of the chair limiting the action of lifting is an anti-affordance. It is a common misconception among designers to describe a property of a product as an affordance. Keep in mind that an AFFORDANCE IS NOT A PROPERTY. They represent relationship between the property of the product and the action it allows performing.
Â
You now know what affordances are. But, what makes an affordance good or bad? The most essential quality of an affordance is discoverability. Affordances exist whether it is visible or not. Perceivable affordances provide strong clues to the operations of the product. Designers must be able to identify optimal ways of using discoverability of affordances and anti-affordances to enrich the experience of the product for its user.
Signifiers
While affordances help determine what actions are possible, signifiers communicate where the action should take place, what is happening and what other possible options exist. People look for signs that may help better understand the functioning of the product. It is the role of designers to put these signifiers in the product to communicate the purpose, structure and operation of the product to the people who use it.
Â
Â
Signifiers can be deliberate and intentional, like a “Tear here” written on a plastic chips bag. They could also be accidental and unintentional, and used for purposes not intended by the designer. The images below show how an unintentional design for preventing people from falling down the stair shaft was used to discard drink containers. This also demonstrates how an affordance can be perceived as a signifier. Once someone realized the affordance of the design to support discarding containers, he/she started using it for that purpose. The discarded container on the support then acted as a signifier to others for discarding their containers in the platform.
Â
Â
Whether they are intentional or accidental, signifiers play an important role in communicating the interactions of your product with people. It is the role of designers to place these clues in the products to help people understand the function of the product.
Mappings
The association between an action and an event is called a mapping. A simple example of mapping is the use of switches to control lights in a room. Mappings are essential for creating a spatial correspondence between the layout of the controls and the products being controlled. Mappings help people better understand the operations of a product and create a model in the mind for simplifying actions. Mappings must be natural for actions of people operating the product to become fluid.
Â
Â
Let’s take some examples. In the image to the left, the stove has a natural mapping for helping people associate which knob controls which burner. There is no need for other intentional mappings to create this association. On the other hand, the stove on the right image has a bad natural mapping for controls and outcome. To make up for the bad mapping, lines are drawn to help create the association for controls. Designers must be able to come up with creative approaches to design mappings based on spatial analogies and help people understand associations between controls and outcomes more intuitively.
Feedback
Feedback is means of communicating the result of an action. A lack of proper feedback mechanisms such as in elevator controls on buildings and pedestrian buttons at street crossings are common examples of failure in communicating an event with the user. The human nervous system is equipped with lots of feedback mechanisms to monitor the body positions and state. Nonetheless, many products seem to place little importance on the natural feedback mechanism of people.
Â
Â
Feedbacks must be immediate. A slight delay in communicating the feedback of actions can cause unsettling feelings. If delays are too long, people often give up and start doing other activities. Feedbacks must be informative enough to let the user know what is going on. Poor feedback can be worse than no feedback. They can annoy the user and create a bad experience with the product. The worst feedbacks are those that are inappropriate and uninterruptible. Feedbacks are important, but they should not get in the way of getting things done. Product designers must plan appropriate, informative and immediate feedback mechanisms in the products.
Conceptual Models
Â
Â
Conceptual models are mental models that people create in their minds of how certain things can be done with a product. They explain on a high-level understanding of how things work. Take a messaging app as an example. People expect that they can send messages back and forth with people elsewhere, and receive notifications when receiving a new message. They are familiar with a user interface that is used in every other messaging app. Attempting to reinvent how text messaging works can cause the users to become frustrated and struggle to learn and remember the new ways of conducting those activities. Creating products whose conceptual models match the mental models of it’s users are essential for creating great experiences.
Designers must be well equipped with an understanding of the user’s mental models to create better experiences with their product.
Â